Rechargeable and non-interchangeable inclosed thermal cut-out.



T. A. MILLER. 'RBGHARGEABLE AND NON-INTERCHANGBABLE INULOSBD THERMAL CUT-OUT. APPLICATION FILED JUNE 13. 1908 93 1,947 Patented Aug. 24, 1909.

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THOMAS ALEXANDER MILLER, OF SOUTH HINGHAM, MASSAGI I USETTSL BEGHARGEABLE NON-INTERCHANGEABLE INCLOSEDTHERMAL CUT-OUT.

Specification of Letters Patent.

Patented Aug. 24,1909.

Application filed June 13, 1908. Serial No. 438,325.

To all whom it may] concern."

Be it known that I, THOMAS A. MILLER, a citizen of the United States, and resident of South Hingham, county of Plymouth, State of Massachusetts, have invented an Improvement in Rechargeable and Non-Interchangeable Inclosed Thermal Cut-Outs, of which the followingdescription, in connection with the accompanying drawing, is a specificatiom like numerals on the drawing representing. like parts.

This invention has for its object the production of an efficient, novel and simple inclosed fuse plug so constructed and arranged that when the fuse has blown a new one can be quickly and. easily substituted without the employment of skilled labor.

I have soarranged the case or box in which the fuse is inclos'ed that only the proper fuse can be used with any particular case, as the latter is held together by the fuse, and thereby I prevent over or under fusing. That is, it is impossible to use a 150 ampere fuse in a 100 ampere case, or any other than a 100 ampere fuse. These and other novel features of my invention will be fully described in the subjoined speci- ,fication and particularly pointed out in the following claims. 1

Figure 1 is a perspective View of a fuse plug embodying one form of my invention, one of the contact or terminal lugs being removed; Fig. 2 is asim-ilar view of a contact or terminal lug; Fig. 3 is a side elevation of the case and the fuse therein, the nearer side of the case being removed; Fig- 1 is a top plan view of the fuse, detached. Fig. 5 1s a transverse section of the case and fuse, on the line 5.5,, Fig. 3, looking toward the left; Fig. 6 is a perspective view of another form of terminal, to be referred to. Fig. 7 is a modification to be referred to.

In accordance with my present invention the fuse plug comprises a fuse proper, and a separable case in which the fuse is inclosed, the parts of the case being held together fuse. The case is made of any suitable insulatmg material, such' as vulcamte, fiber,

etc., and, as herein shown comprises four 5 separate pieces, to wit :top' 1,-bottom 2, and opposite, like sides 3, the ends being made integral or rigid with the top and bottom, the part- {1 of one end having an j together by the fuse itself.

aperture 5, Fig. 1, at its center, said part 41- being shaped as shown to fit closely the complemental end part 6 on the top 1. The sides 3 are shown as provided with sight openings .7, and on their inner 'faces the sides are 7 longitudinally .5, to fit snugly between the top and bottom ribbed or flanged at 8, Fig.

members of the case, the flanges being grooved or undercut at!) to receivea sheet;

of mica or' similar material 10 extending the length of the case, and indicated in Fig. 5 by a heavy line. On the inner faces of the top and bottom membersI forma plurality of dove-tailed or undercut, transverse locking and positioning ribs 11, two of such ribs being shown 011 the top andv two oppositely located ribs on the bottom of the box. These ribs enter with a sliding fit'correspondingly shaped grooves in thefuse, as will be described. i p i The fuse itself is cast, stamped or otherwise formed in a single piece of suitable fuse metal, and as herein shown comprisesfive rectangular enlargements or blocks of the requisite size to snugly fit within the case, integrally connected by bar portions 12 of the fuse metal and of such size as will carry a predetermined current, said portions 12 being the vactual fusing points. The central enlargement 13 has extended through it a bushing 14 of insulating material, internally screw-threaded, to receive the shanks of screws, one of which isshown at 15, F ig; 1, by which the sides 3 are held in place. The two endmost ei'ilargements. 16 are tapped'at 17 to receive the screw-shanks 18 of the terminals or contact lugs 19, shown separately in Fig. 2, the shank being passed through the aperture 5 in the'cnd of the case, and the enlargements are cut away or concaved at 20 to intersect the threaded socketsl'i', in order that a drop of solder may be used to unite the terminal shank and the fuse.

Undercut transverse grooves 21 are formed in the top and bottom faces of ,the inter f mediate enlargements 22 of the fuse, to reonly by the presence and cooperation of the I ceive the locking ribs 11 previously described,

j on the top and bottom of the case, as shown m Fig. 3, and also in Fig. 5,

whereby the top and bottom members 1 and flare locked I. have shown the sight openings? in the f sides of the case aslocated opposite the fus- 5 ing portions 12 of the fuse, so that if the '11 and the grooves 21 of the fuse enlargements' 22, after which the terminals are.

screwed into place and soldered. 'One of the sides is then fitted into place and secured by a screw '15 screwed-==into the bushing 14 of the .central enlargement 13, and if required a the case is filled with asbestos, mica or other noninfiammable, insulating powder, and

, finally the remaining side 3is fitted into place and secured by its screw 15. The fuse plug is now ready for use, the fuse bei g inclosed completely in a tight case, and he case is held together solely by the presence of the fuse, as will be apparent, the whole operation of charging occupying but a few seconds and at the cost of a few cents, viz:

the cost of the fuse.

The fuses are made non-interchangeable by slightly changing the position of the locking. ribs on the top and bottom of the case, with a corresponding change in the grooves in the adjacent enlargements 22 of the fuse. That is, if a 150 ampere case is arranged to fit a 150 ampere fuse, the locking ribs on the case for a 100 ampere fuse will be slightly changed as to position, so that they will fit a 100 ampere fuse, but no other. No substitution of an improper fuse can be made, obviously, for if the fuse does not fit the members of the case cannot be assembled and locked together in operative co dition.

Referring to Fig.- 3 I have sh wn V-shaped abutments 23, 2+1, on the top and bottom, re-

spectively, of the case, between the end and intermediate blocks or enlargements 16, 22, said abutments extending to the fuse portions 12, in order to prevent the interposition of any extraneous metallic connection between said enlargements on the fuse, obviating any possibility of overfusing.

When it is impractical to use contact lugs or terminals such as shown in Figs. 1 and 2 I may employthe form shown at 25, Fig. 6,

to fit over the end and opposite sides of the case, and held in place by a suitable contact screw passed through the hole 26 of the ter- .minal and into the socket 17 of the fuse, and

soldered as before.

Ordinarily a fuse plug is worthless after being blown, as it can only be recharged by sending it to the factory at considerable cost, usually more than it is worth in time and money, but my novel fuse plug can be recharged as often as necessary, at a purely nominal cost, and by any person in a few seconds.

Vere it not for the fact that in themajority of cities the regulations prescribe a fixed connection between the terminals and the fuse, (which I attain by the solder hereinbcfore referred to), obviously the case could be made with a single removable part for the insertion of the fuse, the remainder of the case being a fixture, the cotiperating ribs and grooves onthe, case and fuse respectively preventing the use of fuses of improper capacity, as described, and the re-' movable part would then be held in place only by connection with the fuse, so that the case could not be closed unless a fuse, and the proper one, were first inserted.

It is not necessary that the enlargements be cast integral with the fuse itself, nor are such enlargements necessarily metallic, for

they may be made as separate piecesof the proper dimensions and attached to the fuse bar, as shown in Fig. 7. In said 'figure the fuse bar 27 is provided at each end with a metallic enlargement 28, tapped at 29 as hereinbefore described, but the central and intermediate enlargements, as 30 and 31, Fig. 7, can be conveniently made of insulating material, such as vulcanite, bored to receive the fuse bar and secured thereon by suitable ins 32. The central enlargement is provide with opposite threaded holes 33 to receive the screws 15 previously described, and the enlargements 31 are provided with undercut grooves 34 to receive the locking ribs 11. Should this arrangement be adopted at least one of the metallic end enlargements 28 would have to be made separate from the fuse bar to permit the central and intermediate enlargements to be applied, and a soldered joint or connection would then be made between the bar '27 and the enlargement 28 as a final step in assembling.

Various changes or modifications in different details of construction and arrangement may be made bv those skilled in the art without departing from the spirit and scope of my inventionas set forth in the appended claims. I

Having fully described my invention, what I claim as new and desire to secure by Letters Patent is I 1. In adevice of the class described, a fuse, an inclosing case therefor comprising a plurality of members separable throughout the entire length of the fuse, and means to maintain the members of the casein assembled condition solely by cooperation with the fuse between the ends thereof.

2. In a device of the class described, a fuse, an inclosing case therefor comprising separable top and bottom members and sides,

means to connect and position the top and bottom members by cotiperation with the fuse, and separate means to connect the sides with the fuse and maintain them in operative relation to the top and bottom members.

3. In a device of the class described, a fuse, a case therefor having removable sides, means to position the fuse in the case, and separate fastenings coiiperating with the fuse and the sides to maintain the latter in position to close the case.

4-. In a device of the class described, a case comprising separable top and bottom members having rigid thereon complemental endforming portions,'removable sides, a fuse, means to lock said fuse and the top and bottom members together, and independent means to attach the sides and maintain them in operative position closing the case only when the fuse is in position.

In a device of the class described, acase having a removable side, means to position the fuse in the case and also prevent the use of a fuse of improper capacity, the fuse, and means cooperating solely with the fuse itself to maintain the removable side in position closing the case.

6. In a device of the class described, a fuse having a plurality of rectangular enlargements, threaded terminal sockets in the endmost. enlargements, a multi-partinclosing case for the fuse, means to lock together the top and bottom parts of the case and twp of the fuse enlargements, and separate means to connect the side parts of the case aviththe central enlargement of the ease, the endmost. fuse enlargements being concaved to intersect the terminal sockets.

7. In a device of the class described, aiuse 1 Wing a plurality of integral, separated enargcmeuts, a separable inclosing case for the ise, means to connect the terminals with the endmost enlargementsof the fuse, and means to connect the parts of the case with the other enlargements and maintain the case assembled and closed solely by cotiperation with said enlargements.

8. In a device of the class described, a fuse having a plurality of integral enlargements, undercut, transverse ooves on the opposite faces of some of saiif enlargements, a separable case for the fuse, transverse internal ribs on the top" and bottom thereof to cooperate with the grooves and lock the fuse and said top and bottom together, and separate means to connect the sides of the case and the fuse and maintain the case closed.

9. In a device of the class described, a fuse having a plurality of rectangular enlargements,'integ'ral therewith, a separable rectangular case to receive and inclose the fuse, means on the top and bottom parts of the case to cooperate with and lock together the fuse enlargements and said parts of the case, other means to cooperate with the fuse and the case sides to maintain the latter in position to close the case,'and safety abutments on the interior of the case to extend between a pair of fuse enlargements and prevent an extraneous metallic connection between said enlargements.

it). In a. device of the class described, a multi-part case adapted to receive a fuse of a predetermined capacity and comprising members separable throughout the entire length thereof, and means to maintain the members of the case assembled in closed form only by direct cooperation with an in closed fuse, said means also preventing such cotiperation with a fuse of a different capacity.

In testimony whereof, 1 have signed my name to this specification, in the prese cc of two -subscribing Witnesses.

THOMAS ALEXANDER lllhhlllt.

Witnesses EMILY C. Honors, THOMAS J Dnrmnroxn. 

